Electrical heating system



June 12, 1934. L. B. ROOT ELECTRICAL HEATING SYSTEM Filed March 26, 1931 4 Sheets-Sheet! INVENTOR. XX @y $00 6,

ATTORNEY L. B. ROOT June 12, 1934.

ELECTRICAL HEAT ING SYSTEM Filed March 26. 1931 4 Sheets-Sheet 2 INVENTOR.

05 @m @w a June 12, 1934. ROOT ELECTRICAL HEATING SYSTEM Fild March 26, 1951 4 Sheets-Sheet 3 INVENTOR. 9 44011 69.), @0016, BY

ATTORNEY,.

June 12, 1934. B. ROOT ELECTRICAL HEATING SYSTEM 1951 4 Sheets-Sheet 4 Filed March 25,

ATTORNEY t Patented June 12, 1934 UNITED STATES PATENT OFFICE fourth to Edward L.

Corbett and one-fourth to John C. McDonald, both of New York, N. Y. Application March 26, 1931, Serial No. 525,502

3 Claims.

My invention relates broadly to electrically operated fluid heaters, and more particularly to a compact construction of electrically operated fluid heater which may be economically operated I and which has a minimum number of replaceable parts.

One of the objects of my invention is to provide an electrical heating system in which the fluid to be heated is circulated through a tubular ring which is disposed within the magnetic field of a transformer system and subjected to the effects of eddy currents for raising the temperature of the ring and heating the fluid which is circulated therethrough.

Another object of my invention is to provide a construction of fluid heater constructed in the form of an electrical transformer having a high step-down ratio where the primary winding is electrically connected to an alternating current source and the secondary winding provides a shunt path for the circulation of fluid which is heated by the passage of the fluid around the shunt path formed by the secondary winding.

Still another object of my invention is to provide a construction of induction heater for fluid in which the fluid is introduced into a ring-like secondary winding disposed in the field of a primary winding wherein the secondary winding is subjected to the effects of eddy currents in a closed circuit and the temperature thereof elevated to provide a path for the heating of fluid introduced at one point of the ring and discharged at another point thereof.

A further object of my invention is to provide a construction of electrical heater comprising an electrical transformer having a high step-down ratio where the fleld oi the primary winding is efiective upon a single turn tubular secondary winding which is shunted upon itself, the tubular secondary winding being disposed in a path including a thermostat, a fluid flow switch, and a pressure regulator, and connected between a fluid inlet and a fluid discharge for raising the temperature of the fluid in the course of the passage of fluid from the fluid inlet to the fluid discharge point.

g A still further object of my invention resides in the construction of a combined fluid flow switch and thermostat for controlling the passage of fluid through a tubular secondary member in an induction type electric heater for predetermining the temperature condition of the fluid heated by the electric heater.

Other and further objects of my invention will be understood from the specification hereinafter following by reference to the accompanying drawings, in which:

Figure 1 is an electrically operated fluid heater constructed in accordance with my invention, parts of the casing being broken away and shown in section; Fig. 2 is a central vertical longitudinal sectional view on an enlarged scale taken on line 2--2 of Fig. 3; Fig. 3 is a detailed horizontal sectional view taken on line 33 of Fig. 2; Fig. 4 is a vertical transverse sectional view taken on line 4-4 of Fig. 2; Fig. 5 is a vertical sectional view of the combined flow switch and thermostat taken on line 5-5 of Fig. 6; Fig. 6 is a sectional view taken on line 6--6 of Fig. 5; and Fig. '7 is a detailed horizontal sectional view taken on line 79,. 7-7 of Fig. 5.

Referring to the drawings in detail, reference character 1 designates a casing which encloses the fluid heating apparatus. The casing has a suitable cover 2 extending thereover and provides 75, a housing for the electrical transformer system 3. The transformer system 3 includes a closed core 4 on one leg of which the primary winding 5 is wound, the turns being disposed on a suitable spool-like frame 6. The spool 6 is mounted on 80, one leg of the core 4 in such manner that the magnetic lines of force from the primary winding 5 passes around the core 4 and thread the secondary winding 7 which is disposed on the leg 8 0i the core structure 4. The secondary winding '7 85, consists of a. hollow metallic tubular member which encircles the leg 8 of the core 4 and has the ends thereof electrically interconnected by a weld or other conductive joint represented at 9. The secondary turn 7 is housed within a heat insulating casing designated at '10 which fits around the leg 8 of the core structure 4. The casing 7 is boxlike in contour and has the ends '71 and '12 thereof in abutment with the upper and lower portions of the core structure 4. The interior of the boxlike casing '10 is fllled with heat insulating packing such as asbestos or other heat insulating material designated at 73 which is compacted around the leg 8 of the core structure be.- tween the leg 8 and the interior of the tubular turn 7 and around the exterior of the tubular turn 7 and within casing '10. The heat insulating packing '73 and the insulating casing '70 reduce the loss of heat which would otherwise occur by radiation conduction and convection from the tubular turn '7. The casing '70 assimilates in contour the shape and size of the primary winding 5 and occupies a space on the leg 8 of the core structure similar to the space occupied by the winding 5 on the opposite leg of the core struc- 1 10 ture. The casing and packing 73 tend to confine the heat around the secondary winding 7, thereby lowering the time interval required for raising the fluid to desired temperature. The ends of the hollow tubular conductor 7 extend in a vertical direction as represented generally at 10 and are bent horizontally and extended to one side of the casing 1, providing an inlet fluid connection at 11 and an outlet fluid connection at 12. The fluid supply is connected to the fluid inlet connection 11. The discharge or outlet pipe 12 is connected to a pipe line or faucet or other conductor where the heated fluid is to be utilized. The heating of the fluid is effected within the circuitous path around the hollow tubular conductor 7.

It will be observed that the hollow tubular conductor 7 constituting the secondary winding is disposed in a plane coincident with the plane of the turns of the primary winding 5 and is subject to the inductive effects thereof. The induced current in the hollow tubular member 7 traverses a shunt path inasmuch as the discharge end 12a directly connects with the inlet end 11a of the hollow tubular member '7. The current which is built up in the shunt path is of high amplitude for the reason that the transformer is wound in a large step down ratio. The short-circuited turn is traversed by eddy currents under the inductive effects of the primary winding 5 and is raised in temperature to impart heat to the fluid which traverses the circuitous path through the secondary turn '7. High temperature is developed in the shunt path 7 and accordingly a large degree of heat is imparted to the fluid which traverses the circulatory path through the shunt turns 7. The secondary winding 7 being a continuation of the inlet tube and the discharge tube 12 permits heating of the entire tube system by conduction permitting the fluid to be maintained at high temperature.

In order to regulate the heating of the fluid, I arrange in the path of the discharge pipe 12 a combined flow switch and thermostat represented at 14. I also provide in series with the discharge pipe 12 a pressure regulator designated generally at 15. The combined thermostat and flow switch which is arranged in the unit 14 is constituted by a casing having an upper section 16 and a lower section 17. The heated fluid enters the lower section 17 from the pipe 12a through the connection 18. The water leading to the discharge pipe 12 leaves the lower section 17 through the outlet 19. Lower section 17 is divided into a pair of cylindrical chambers 20 and 21, the ends of which are closed by plugs 22 and 23, respectively. Chamber 20 includes a thermostat tube represented at 24 which passes through the bushing or plug 35 into the upper section 16 of casing 14. The cylindrical chamber 21 contains the flow controlling piston 26 which is provided with bleeder apertures 27 permitting the passage of fluid and preventing the switch mechanism hereinafter described, from operating if the valve or faucet at the point where the fluid is used should develop a leak. The operating mechanism disposed between the flow switch and the thermostat includes a quick action device responsive to the temperature and flow conditions of the fluid. The end of the thermostat 24 connects to the system of motion multiplying levers designated at 28. A lever 29 is pivotally mounted at 30 and is actuated at one end by the end of the thermostat 24. The opposite end of lever 29 is pivotally connected at 31 to link 32 which connects to lever 34 through pivotal connection 35, the lever 34 being pivoted at 36 on the mounting device 36. The end of the motion multiplying lever 34 connects to the actuating arm 37 having a bearing member 38 rockably connected with one end of the laterally extending yoke 39. The opposite end of the yoke 39 is actuated by the end of the flow controlling piston 26 which has the actuating stem 46 thereon connected through the rockable connection 41 with the yoke 39. The yoke 39 is provided at its center with a bearing member 42 which is centered in the laterally extending member 43. The member 43 is secured to the laterally extending member 44 on which the pairs of lever 45 and 46 are pivotally mounted. The pairs of lever arms have rod members 45a and 46a extending therethrough between which the springs 47 are interconnected for actuating the sets of levers according to a snap action. The ends of levers 46 are pivotally mounted at 49 with respect to the link member 50 which extends through the intermediate partition member 51 in casing 14 and through the insulated support 52 to the insulated support 53 which is carried by the link member 50. The insulated support 52 carries electrical contacts indicated at 54 which may be aligned with the contacts 55 which are carried by the movable member 53 and adapted to be closed with respect to the contacts 54 when the link 50 is moved vertically. A limiting collar 56 is adjustably mounted on the link 50 for providing an abutment with the partition 51 when the link 50 is shifted to its extreme upper position. The extreme upper position of the link 56 serves to close the electrical contacts 54 and 55. The contacts 54 and 55 are disposed in series with the primary winding 5 to show that the electrical circuit through the primary winding 5 is controlled in accordance with the temperature conditions and the flow of the fluid through the circulatory system. The piston member 26 serves to shut off the flow of fluid from the portion 20 of the lower section 17 to the outlet. The piston 26 operates against the spring 57, the spring being disposed between the bushings 58 and the collar 59 on the stem 40. The bushin 58 enters the partition member 51 in the casing and passes through a suitable packing designated at 58 to prevent leakage of the fluid. In series with the discharge pipe 12 I provide the pressure regulator 15 which permits the discharge of fluid under predetermined pressure conditions which may be regulated by the adjustment of the screw device 60 against spring 61 controlling the position of valve 62 with respect to the passage 63.

The thermostat and fluid flow switch are contained within the unit as designated at 14. On turning on the water on the outlet side of the heater at a faucet such as at 12, water is caused to flow through the thermostat chamber 20 forcing plunger 27 down and causing the yoke 39 to move in a downward direction. The spring members or knuckles 45 and 46 are moved past dead center causing the springs 47 to snap the switch consisting of contacts 54 and 55, closed. This operation closes the circuit through the secondary winding 5 thereby energizing the transformer system. In the event that plunger 26 is forced down in a position closing the outlet 19, and the temperature of the fluid in chamber 20 should rise above the required predetermined temperature, the thermostat 24 is operated forcing plunger 64 upwardly which operates through a train of levers 29, 32 and 34 to raise the knuckles or spring tension members 45 and 46 past dead 

